JPH03263471A - Colorant composition and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in gradation, image density and fixity and useful as a liquid developer for electrophotography, a coating material, a printing ink, etc., by the flushing method using a pigment and a fluorine-based oil. CONSTITUTION:The objective composition is obtained by the flushing method using at least a pigment (e.g. carbon black or phthalocyanine blue), a fluorine- based oil (preferably perfluoro-based oil), humic acid (salt) and a humic acid derivative.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a colorant used in electrophotographic liquid developers, paints, printing inks, and the like.

[Prior Art] For example, paints, printing inks, etc. or colorants obtained by kneading organic or inorganic pigments such as carbon block and phthalocyanine blue with resin and pulverizing the toner are used as carriers with high insulation and low dielectric constant. Liquid developers for electrophotography, which are uniformly dispersed in a liquid, have been well known.

However, since organic or inorganic pigments in these colorants usually have strong secondary aggregation, they cannot be easily dispersed into primary particles even if dispersed in a vehicle using a ball mill, attritor, hot roll mill, etc. Ta.

By the way, the flushing method (specially known as the flashing method) in which a colorant is produced by dispersing carbon black or the like in water, then kneading it with a resin solution to replace the water surrounding the carbon black with the resin solution, and then removing the water and solvent. JP-A No. 56-80055 and JP-A No. 58-141.41) are known.

However, even with this flushing method, since carbon black is not hydrophilic, it does not disperse well in water and cannot be made into fine particles, and as described above, it is difficult to disperse the carbon black into secondary particles.

Colorants produced using such conventional flushing methods are used in electrophotographic toner particles 12 and electrophotographic liquid developers 1. In this case, it was difficult to form an image with high density and excellent gradation and fixing properties because the dispersibility in the carrier liquid was insufficient.

However, as an improvement to the method for producing colorants using such flushing method, (a) When dispersing colorants such as carbon black in water, anionic, nonionic or cationic surfactants, synthetic polymer dispersants, etc. (b) Using humic acid, humic acid salts, or humic acid derivatives, a coloring agent such as carbon black is dispersed, and then low molecular weight polyethylene, natural resin-modified resin, dammar, copal, shellac, gum rosin, styrene, etc. A method of kneading butadiene copolymer, polyolefin, etc. to coat pigment particles has been studied or disclosed (Japanese Unexamined Patent Publication No. 102253/1983).

However, the coloring agent obtained by the above method (a) has a drawback that its dispersibility in the carrier liquid is still not 1. In addition, the colorant obtained by methods j and ゛ of above (b) cannot necessarily be blended sufficiently with other resins,
Therefore, it has the disadvantage of being somewhat inferior in adhesion, gradation, and image density.

[Problems to be Solved by the Invention] The present invention provides a coloring agent for use in electrophotographic toners, paints, printing inks, etc. that can be particularly well-fixed or adhered to paper, wood, metal plates, etc., and has particularly good gradation and image density. It is intended to provide an agent for

[Means for Solving the Problems] As a result of intensive studies to solve the above-mentioned problems, the present inventors discovered that it is effective to mix fluorine-based oil or humic acid etc. with the pigment. , led to the present invention.

That is, the present invention provides (1) a colorant composition containing at least a pigment and a fluorine-based oil as main components; (2) a colorant composition according to the above (1), which is prepared by a flushing method from at least a pigment and a fluorine-based oil; (8) A method of producing the colorant composition described in (1) above from at least a pigment, a fluorine-based oil, and humic acid, a humic acid salt, or a humic acid derivative by a flushing method.

The present invention will now be explained in more detail.

First, the following can be exemplified as the pigment (carbon black, organic pigment) used in the present invention.

As carbon black, furnace black, acetylene black, channel black, etc. can all be used, and commercially available products include Printex G, Special Black 15, Special Black 4, Special Black 4-B (manufactured by Degussa), and Nikubishi #44. , #30, H
A-11, M^-1oo c or more manufactured by Mitsubishi Carbon Corporation),
Raven 30, Raven 40, Conductex SC (
(manufactured by Columbia Carbon), Regal 800.40
0.660 and Black Vernil L (manufactured by Cabot) are known.

Organic pigments include Phthalocyanine Blue, Phthalocyanine Green, Sky Blue, Rhodamine Lake, Malachite Green Lake, Methyl Violet Lake, Peacock Blue Lake, Naphthol Green B1 Naphthol Green Y1 Naphthol Yellow 81 Lysol Fast Yellow 2G, Permanent Red 4R, Brilliant Fast Scarlet, Banza Yellow, Benzidine Yellow, Risol Red, Rake Red C, Ruki Red D, Brilliant Carmine 6B1 Permanent Red P5R, Pigment Scarlet 3B and Bordeaux 1
Examples include 0B.

The fluorine-based oil used in the present invention is a hydrocarbon-based oil in which hydrogen is replaced with fluorine, and preferably perfluorinated oil. Among these, particularly preferred examples are shown in the table along with physical property values.

The amount of these fluorine-based oils used is 0 per part by weight of pigment.
．． 01 to 8.0 parts by weight, preferably 0.1 to 2.0 parts by weight.

In addition, a part of the fluorine-based oil may be replaced with the above-mentioned natural resin-modified coal resin, natural resin-modified maleic acid resin, dammar,
It is possible to substitute copal, shellac, gum rosin, hardened rosin, ester gum glycerin ester modified maleic acid resin, styrene-butadiene copolymer, polyolefin, copolymer with polyolefin, wax, etc., but in that case, , at least 50% by weight of the entire resin (including waxes) must be fluorine oil.

In one aspect of the present invention, a coloring agent in which a pigment is coated with a fluorine-based oil or the like is obtained by a flushing method, but in another aspect of the present invention, a coloring agent in which a pigment is coated with a fluorine-based oil or the like is obtained by a flushing method. obtained using derivatives.

Humic acid is an alkali-soluble amorphous polymeric organic acid contained in young coals such as peat and lignite with a low degree of coalification. Humic acids are broadly classified into natural products and artificial products (including trophumic acid), and both can be used in the present invention. Industrial products of humic acid are classified into CH type, CHA type and CHN type depending on the molecular weight distribution, and each type is acid type or, for example, Na, NH
There are salt types such as No. 4, and any of them can be used.

Since humic acid, humic acid salts, or humic acid derivatives (hereinafter referred to as "humic acids") are well adsorbed to pigments, they are advantageous for atomization and dispersion to approximation of next-order particles and for improving dispersion stability (long-term storage). It is.

The colorant is manufactured using the above raw materials in the following manner. Add humic acids to the pigment water-containing liquid at a concentration of 0.1 to 30% of the pigment water-containing liquid.
% by weight and mixed well in a kneader, or a pigment water-containing liquid to which no humic acids are added, is further mixed well with fluorine oil, etc. in a kneader called a flasher. As a result, water existing around the pigment is replaced by fluorine oil or the like. The water is discarded from this, and the pigment dispersed in fluorine oil or the like is dried to obtain a lump. Colorant powder is then obtained by crushing this mass. This colorant has pigment in the form of primary particles coated with a fluorine oil or the like, and is useful for printing inks, paints, electrostatic photographic toners, and the like.

For example, in order to prepare an electrostatographic liquid developer using the colorant produced as described above, the colorant may be dispersed in a carrier liquid together with a binder resin.

As a carrier liquid, highly insulating (electrical resistance 101@Ω・cm
above), low dielectric constant (dielectric constant 3 or less) petroleum aliphatic hydrocarbons, n-hexane, ligroin, n-hebutane, n-
Other examples include pentane, indodecane, isooctane, and their halogen derivatives such as carbon tetrachloride, perchlorethylene, and the like. Commercially available petroleum aliphatic hydrocarbons include Isopar E, Isopar G1 Isopar L1 Isopar H, Isopar 1 Naphtha No. 6, and Tsurpez 100 manufactured by Exxon.
Using fluorine oil as a dispersion medium is more effective. These may be used alone or in combination.

Next, examples and comparative examples will be shown.

Example 1 Water 500g Printex 30g Alkali Blue 20g Humic acid 10g in a flasher
After stirring well, perfluorocyclohexane 6
00g was added to the flasher and kneaded. Subsequently, the mixture was heated, and water was removed under reduced pressure to obtain a coloring agent paste with a water content of 0.50%.

Examples 2 to 0 Nine types of colorants were produced in the same manner as in Example 1, except that the raw materials were replaced with those shown in Table 1.

Table 1 Using these developers, a commercially available copying machine (Copy DT-200 manufactured by Ricopy Co., Ltd.) was subjected to T-Picture.The results shown in Table 2 were obtained.

MRP: Trade name for rosin-modified maleic acid resin manufactured by Hitachi Chemical Co., Ltd. BR-898E Trade name for methyl methacrylate resin manufactured by Hishi Rayon Co., Ltd. In addition, 100 g of these colorants were added to 50 g of polylauryl methacrylate/acrylic acid (90/10). The mixture was added to 100 g of perfluorocyclohexane and kneaded in a ball mill for 72 hours to make a concentrated toner.
．． A developer was prepared by dispersing No. 9 in perfluorocyclohexane.

1 [Note] Fixability...A/BX100 A is solid image density, B is Clockmark the solid image area. 5 times with eraser tester image density after

Image density: Reflection densitometer RD-514 manufactured by Macbeth
Measurement of the solid area of the image density.

Gradation: Kogutsuku Grayscale Copy 20 times and reproduce the gradation Assess gender. Presence of concentration difference Determine nothingness with 11 visions.

2 [Effects of the Invention] As explained above, the present invention has good gradation, image density, and fixing performance. In addition, when carbon black is used as a pigment, the degree of blackness can be further increased.
This is considered to indicate that carbon black is well dispersed in the flushing colorant of the present invention.

Claims (3)

[Claims] (1) A colorant composition containing at least a pigment and a fluorine oil as main components. (2) A method for producing the colorant composition according to claim (1) from at least a pigment and a fluorine-based oil by a flushing method. (3) A method for producing the colorant composition according to claim (1) from at least a pigment, a fluorine-based oil, and humic acid, a humic acid salt, or a humic acid derivative by a flushing method.